I would definitely agree that it can become an awkward situation if parents don't tread with some care and tact - especially if one child passes and not the other. We all believe that our child would benefit immensely from a place and has worked hard enough to deserve it , so any feelings of jealousy or even slight bitterness when faced with unwelcome news is understandable. It all happens so quickly too - before the parent has even come to terms with anything, they need to bear other people's news too or answer questions. I think some people just don't have the social skills to negotiate the situation: parents with good news might be insensitive when they go on about how they just can't believe it how great it is and disappointed parents might make a snide remark without realising its impact. Very few people actually intend to be mean.
Also, parents of the same school don't actually need to ask each other in the playground as they will find out from the children anyway when they get home. I remember a rush of parents asking me what DS got as I walked into the playground after school even though I wanted to be low key about it. Luckily, I had good news but I remember being very weary that there might be someone who had bad news in earshot and thinking that if DS had not got in I / we would have found it quite devastating to keep telling everyone

- playground discussion on results day should be a big No No.
I had a deal with my group of friends last year: once we get our results we will send a simple no-frills text to let each other know, but say no more. After that, it would be up to anyone whose child did not get in to make contact when they are ready. That way everyone knew what the deal was and it worked well. I also told DS to be very low key at school because there would be several of his friends who did not a place and he should not contribute to any disappointment they might be feeling.
It is not easy, but some common sense goes a long way!
UmSusu